Electric spark ignition apparatus



Dec. 14, 1954 E. W. LAUTENBERGER ELECTRIC SPARK IGNITION APPARATUS Filed Sept. 27, 1952 Fig.1.

' Inventor: Elmer W Lautenberger; by pfxzaua His Attorney United States atent ()fitice 2,697,184

Patented Dec. 14, 1954 grain of a similar apparatus for simultaneous firing of a plurality of spark plugs. 2 697.184 Referring now to the drawing, and more'particularly ELECTRIC PARK IGNITION APPARATUS a pacitor and an auxiliary capacitor 2 connected to be Elmer W. Laiitenberger, Scotia, N. Y., assigiior to Gendirectional current supply including a rectifier 3 and an oral Electric Company, a corporation of New York autotransformer 4. The main capacitor 1 is connected directly across the charging source, the auxiliary capacitor Apilheatwh September 1952, Semi 3119934 2 is connected across the source in series circuit relation 14 maims. (Cl. with a current limitingres stor 5. The primary portion of My invention relates to electric spark ignition apparal5 6. It will be evident to those skilled in the art that tus, and more particularly to capacitive discharge ignition through this charging circuit the capacitors 1 and 2 are equipment for igniting combustible mixtures of air and simultaneously charged in a series of increments, the uel in apparatus where precise timing is not necessai llun'lbel 0f Increments Of Course depending upon the he present appl cat on s a cont nuat on of my applicapacity 0f the capacitors and the autotransformer output tionSerial No. 256,484, filed November 15, 1951. voltage.

In aircraft gas turbines or jet engines, difliculty has Connected across the main capacitor 1 I provide a main heretofore been experienced in lighting or relighting burridischarge circuit comprising, in series circuit relation, a ers at high altitudes and high air speed. It has been scaled spark discharge device 9, the'high voltage secondfound that high energy capacitor discharge spark ignition y wlhdlhg 14} of a p- P transfemlel 11 having p is better suited to this use than are inductive spark ignimaiy winding 12, and a pair of spaced apart ignition elec tiOHSYSfBZllS. The timing and repetition rate of the spark tmdes 13 which y for p be P Ovided y a spa k are not critical or even of any great signiticance, but the pl s 0? ny esir d type. The sealed discharge device 9 energy content of each discharge must be quite high and eempflses 5 P f Sparking eleetredes disposed in Spaced should be maintained substantially constant and independapart relation wilhin a sealed envelope, and preferably the ent f l i d d i d envelope is filledwith arr-inert gas at a desired and sub- Accordingly, therefore, it is a general object of my inantially constant density. The breakdown voltage of vention to provide new and improved electric spark igni- Such P 15 Substantially eohstent despite temperature {ion apparatus 0f tne capacitor discharge type and resultant PZ'CSSUIE cnan es 1D the inert gas The igni- It is another object of my invention to provide electric h electrodes 33 are Preferably the electredes of an p spark ignition apparatus having a spark of high and sub- 35 J' F P 8 p yp pa Plug, Such 38 1'8 ShOWII, fer nstantially constant energy content, ple, in Patent 2,465,092, issued to J. R. Harkness et al.

It is a more specific object of my invention to provide on Mafeh 2 1 e e y also, the fiXed r i tanCe a new and imp gved capacitor discharge park ignitign Of this 11181 11 ddSCh'ctIgE CliCllllT, 6., GXClLiSlVe Of the arc apparatus f ai raft gas bi or j engines hi h paths therein, is considerablylessthan the critical value at shall provide a high energy spark substantially iridepend- 40 Whleh bselllatofy dlseharge beglhs, 80 that discharge y ent of altitude and air speed, whereby the engine burne osclhatory- It W111 of eeurse be appreciated y these ers may be started or restarted readily at any altitude. sklned the t that the degree of p g and h s h Another object of my invention is to provide a capacitor nature of the h ge P I upon the entire circuit di h i i i apparatus hi h ll comprehend a resistance. The circuit resistance includes the ignition minimum number of parts and shall thus be light in Weight are and Sealed p are, and these ares y in r sistand inexpensive, but shall nonetheless be dependable and ahce during the ee bl i operdtiml- Across the auxiliary d scharge capacitor 2 I connect an In carrying out my invention in one form I provide a uxiliary discharge circuit which includes, in series circuit main discharge or energy storage capacitor and an auxl'elattohz the Sealed spark discharge device 9 and the P iliary triggering capacitor, both connected to be charged 59 l Wlndlng 12 0f the p- P tlarlsformer 11 Preferrom any suitable source of electric current supply The e ly the fixed resistance of this auxiliary discharge circuit main discharge capacitoris provided h a discharge is also less than the critical value so that discharges therecuit including, in series circuit relation, 21 pair of spark through may b f an illatory nature, although the i i i electrodes, the secondary winding of a step up character of this discharge also depends upon the resisttransformer and a sealed spark gap. The auxiliary trigance t Sealed el are gering capacitor is provided with a triggering discharge R W now be evldeht that In e h e Capacitors circuit which includes, in series circuit relation, a primary 1 2 are Charged In Perehel elrelllt relation and in Winding of the step-up transformer d h same sealed 2.1861168 of charging increments from the unidirectional of the main capacitor. In this circuit the sealed gap acts 60 Contact 6, the w 'ansfoljiner 4 and the air speed so that discharge cannot be initiated until the mg capacltor 2 attains a Pfedetermlned d sir d value capacitors are charged to a predetermined voltage When she f f eXample; about 3 0r 3 5 l lts, the sealed such predetermined voltage is attained, the sealed gap Shark dlscharge devlee 9 breaks n riOniZeS, and a ionizes and the auxiliary capacitor discharges through the h e 'isj takes Place through the a xiliary ischarge sealed gap and the trannsformer primary Winding. This c1r?u1t.1nludmg the trinsformef Pnmary Wmdmg auxiliary discharge current induces in the transformer sec- 18 h amen? Induces i the m'f Sec ondary Winding a high. impulse voltage The high ondary winding 10 a high voltage impulse. This induced volta e may, for example, be of the order of 16 to 17 duqed Yohage acids the mam Capacltor vqltag-e m the kilovglts, and is of high frequency if the discharge of his manvarious ob ects and advantages more fully appr t ner, discharge of the capacitor 2 through the auxiliary y referring h following detalhtd speelficatloh discharge circuit immediately and positively effects a dis- Iakeh In colllunetloh Wlth the accompanying drawing, In charge or the main capacitor 1 through the main diswhich Fig 1 is a schematic circuit diagram of an electric c arge circuit including the ignition electrodes or spark spark ignition apparatus embodying my invention in one plug 13 In this operation the current limiting resistor form, ig 2 is a schematic circuit diagram of a similar 5 serves to prevent discharge of the main capacitor 1 apparatus applied to a spark ignition systemof the vopthrough the transformer primary winding 12 to ground At Fig. 2 I have shown another embodiment of my invention similar to that shown at Fig. 1 but applied to an ignition system of the type known as an opposite polarity system. Those elements of the circuit of Fig. 2 which correspond to like elements in the circuit of Fig. 1 have been identified by the same reference numerals. At fig 2 I have shown a pair of spaced apart high voltage ignition electrodes 13a which may be the insulated high voltage electrodes of aipair of single-electrode spark plugs. The electrodes 13a are connected in the discharge circuit of the main discharge capacitor 1 in series circuit relation with the sealed spark discharge device 9 and the high voltage secondary windings 10 and 10a of two step-up transformers 11 and 11a. The transformers are provided respectively with primary windings 12 and 12a, and the primary windings are connected in parallel circuit in the discharge circuit of the auxiliary or triggering capacitor 2. The step-up transformer secondary windings 10 and 10a are so connected in the main discharge circuit that one terminal of each such secondary winding is directly connected to a separate one of the ignition electrodes 13a. The operation of the circuit shown at Fig. 2 is entirely similar to the operation of the circuit shown at Fig. 1, except that high triggering voltages are induced in the secondary windings of both the step-up transformers 11 and 11a, and these transformers are so disposed that the induced voltages are of opposite polarity thereby to increase the voltage available for discharge between the ignition electrodes 13a.

At Fig. 3 I have shown my apparatus applied for simultaneous firing of more than one ignitor plug. The circuit of Fig. 3 is similar to that of Fig. 1, and like parts have been assigned the same reference numerals. At Fig. 3, however, I have shown two double electrode ignitor plugs 14 and 14a connected in parallel circuit relation in the main discharge circuit of the capacitor 1. Each branch of the parallel circuit includes also the secondary winding of a high frequency impulse transformer, the maincapacitor 1 and sealed gap 9 being in the common part of the main discharge circuit. Thus, the plug 14 is in series with the secondary winding 10 of the transformer 11, and the plug 14a is in series with a secondary winding 10a of a transformer 11a, both these circuits being supplied in parallel from the capacitor 1 through the sealed gap 9. The transformer primary windings 12 and 12a are shown connected in parallel circuit relation in the triggering circuit. It will of course be understood by those skilled in the art that a single primary winding in inductive relation with each of a plurality of secondary windings could if desired. Similar parallel connections of transformer secondary windings may be multiplied to fire any desired number of ignitor plugs through a common main discharge circuit.

While I have described and illustrated only certain preferred embodiments of my invention by way of example, many modifications will occur to those skilled in the art, and I therefore wish to have it understood that I intend in the appended claims to cover all such modifications as fall within the true spirit and scope of my invention.

What I claim as new and desire to Patent of the United States is:

1. In an electric spark ignition apparatus for supplying a recurrent arc discharge between a pair of spark ignition electrodes, a pair of capacitors, unidirectional electric current supply means connected to charge said capacitors, a spark discharge device having a sealed envelope, at step-up transformer having a low voltage primary winding and a high voltage secondary winding, means for connecting said spark discharge device and said transformer secondary winding across one of said capacitors in a main series discharge circuit including said ignition electrodes, and means connecting said transformer primary winding and said spark discharge device across the other said capacitor in an auxiliary series discharge circuit, whereby discharge of said other capacitor through said auxiliary circuit triggers said main series discharge circuit through said transformer.

2. In an electric spark ignition apparatus for supplying a recurrent arc discharge between a pair of ignition electrodes, a pair of supply conductors, a main capacitor connected between said conductors, an auxiliary capacitor connected between said conductors in series circuit relatron with a current limiting resistor, a spark discharge new and improved ignition secure by Letters be utilized device including a pair of sparking electrodes disposed in spaced apart relation in a sealed envelope, one said sparking electrode being connected to the common terminal of said capacitors, a step-up transformer having a low voltage primary winding and a high voltage secondary winding, means for connecting said spark discharge device and said transformer secondary winding across one of said capacitors in a main series discharge circuit including said ignition electrodes, and means connecting said primary winding and said spark discharge device across the other said an auxiliary series discharge circuit, whereby discharge of said other capacitor through said auxiliary series discharge circuit triggers said main series discharge circuit through said transformer.

3. In an electric spark ignition apparatus for supplying a recurrent arc discharge between a pair of ignition electrodes, a pair of capacitors, means including a source of pulsating electric current supply for charging said capacitors in a series of increments, a spark discharge device having a sealed envelope, a step-up transformerhaving a low voltage primary winding and a high voltage secondary winding, means for connecting said spark discharge device and said transformer secondary winding across one of said capacitors in a main series discharge circuit including said ignition electrodes, the fixed resistance of said main discharge circuit being less than the critical value for preventing oscillation, and means connecting said transformer primary winding and said spark discharge device across the other said capacitor in an auxiliary series discharge circuit, the fixed resistance of said auxiliary discharge circuit being less than the critical value for oscillation, whereby discharge of said other capacitor through said auxiliary circuit triggers said main discharge circuit through said transformer.

4. In an electric spark ignition apparatus for supplying a recurrent arc discharge between a pair of ignition electrodes, a pair of capacitors, unidirectional electric current supply means connected to charge said capacitors, a spark discharge device having a sealed envelope, a pair of step-up transformers having lowvoltage, primary windings an high voltage secondary windings, means said spark discharge device and said transformer secondary windings across one of said capacitors in a main series discharge circuit including said ignition electrodes, said ignition electrodes being adapted to be interposed between said secondary windings in said main series ischarge circuit, and means connecting said primary windings in parallel circuit relation with each other and in series circuit relation with said spark discharge device across the other said capacitor thereby to provide an auxiliary series discharge circuit, said other capacitor through said auxiliary circuit triggers said main discharge circuit through said transformers.

an electric spark ignition apparatus for supplying a recurrent arc discharge between a pair of ignition electrodes, a pair of supply conductors, a main capacitor connected between said conductors, an auxiliary capacitor connected between said conductors in series circuit relation with a current limiting resistor, a spark discharge device including a pair of sparking electrodes disposed in spaced apart relation within a sealed envelope, one said sparking electrode being connected to the common terminal of said capacitors, a pair of step-up transformers each having a low voltage primary winding and a big voltage secondary winding, means for connecting sat spark discharge device and said transformer secondary windings across said main capacitor in a main series discharge circuit including said ignition electrodes, said ignition electrodes being adapted to be interposed between said secondary windings in said main series discharge circuit, and means connecting said transformer primary windings in parallel circuit relation with each other and in series circuit relation with said spark discharge device across said auxiliary capacitor thereby to provide an auxiliary series discharge circuit, whereby discharge of said auxiliary capacitor triggers said main discharge circuit through said transformers.

6. In an electric spark ignition apparatus for supplying a recurrent arc discharge between a pair of spark ignition electrodes, a main energy storage capacitor, a source of unidirectional electric current supply connected tc charge said capacitor, a spark discharge device having a sealed envelope, a step-up transformer having a lovs voltage primary winding and a high voltage secondar winding, means for connecting said and said transformer secondary winding across said elimeans including said tors in parallel circuit relation, step-up transformer means an auxiliary capacitor for recurrently inducing in said including a plurality of secondary windings and primary transformer secondary winding a high impulse voltage in winding means inductively coupled therewith, a single response to recurrent conduction through said spark dissealed spark discharge device connecting said spark plugs Charge device thereby recurrently to initiate current disin parallel circuit relation across said main capacitor each charge through said main discharge circuit. in series with one said secondary winding, and means 7. In an electric spark ignition apparatus for supplyconnecting said primary winding means and said sealed ing a recurrent arc discharge between a pair of spark ignispark discharge device in series circuit relation across tion electrodes, a main energy storage capacitor, a source said auxiliary capacitor of unidirectional electric current supply connected to In an electric spark ignition apparatus for supplycharge said capacitor, a spark discharge device having mg a recurrent arc discharge between a pair of spark a sealed envelope, a step-up transformer having a loW ignition electrodes, an energy storage capacitor adapted voltage primary winding and a high voltage secondary to be connected to discharge between said electrodes a winding, means for connecting said spark discharge device spark discharge device having a sealed envelope and and said transformer secondary winding across said enadapted to be connected in circuit between said capaciergy storage capacitor in a main series discharge circuit tor and said electrodes to control said discharge and including connections for said ignition electrodes, an auX- means including said device for recurrently impressing iliary capacitor, and means connecting said auxiliary caupon said circuit a high impulse voltage thereby recurpacitor in series circuit relation with said transformer priiently to release said energy. may winding and said spark discharge device thereby 12. In an electric spark ignition apparatus for supplyrecurrently to induce in said transformer secondary winding a recurrent arc discharge between a pair of spark ing a high impulse voltage in response to recurrent voltignition electrodes connected in series circuit relation age breakdown of said spark discharge device, said high with a discharge device having a sealed envelope means impulse voltage initiating a discharge current in said main responsive to voltage breakdown of said device for imdischarge circuit. pressing on said circuit a high impulse voltage thereby 8. In an electric spark ignition apparatus for supplyto initiate discharge between Said l trodes. ing a recurrent arc discharge between a plurality of coop- 13. In an electric spark ignition apparatus for superating pairs of spark ignition electrodes, a main enplying an arc discharge between a pair of spark igniergy storage capacitor, a source of unidirectional electron electrodes, main and auxiliary capacitors, unidirectric current supply connected to charge said capacitor a tional electric current supply means connected to charge spark discharge device having a sealed envelope transsaid main capacitor, a single spark discharge device conormer means including a plurality of high voltage secnected in charge changing circuit relationship with both ondary windings and low voltage primary winding means of said capacitors, a step-up transformer having a low inductively coupled with said secondary windings means voltage primary winding connected in charge changing connecting said secondary windings in parallel circuit circuit relationship with said auxiliary capacitor and said relation each branch of said parallel circuit includin discharge device, s transformer including a high voltconnections for one said pair of said spark ignition elecage secondary winding connected in series with said distrodes, means connecting said parallel circuit in series charge device and said electrodes across said main capacicircuit relation with said spark discharge device across tor. said main capacitor thereby to provide a main discharge 14. In an electric spark ignition apparatus for supplycircuit, and means including said primary winding means mg an arc discharge between a pair of spark ignition elecand an auxiliary capacitor for recurrently inducing in said trodes, mam and auxiliary capacitors, unidirectional elecsecondary windings high impulse voltages in response to tric current supply means connected to charge said mam iecurrent conduction through said spark discharge device capacitor, a single spark discharge device connected in thereby recurrently to initiate parallel current discharge charge changing circuit relationship with both of said through said main circuit. capacitors, a step-up transformer having a low voltage 9. In an electric spark ignition apparatus for supplyprimary winding connected in charge c anging circuit ing recurrent arc discharges between a plurality of pairs relationship with said auxiliary capacitor and said disof spark ignition electrodes, a pair of capacitors unidicharge device, said transformer including a high voltage rectlonal electric current supply means connected to secondary winding connected in series with said dis- 0 arge said capacitors, a spark discharge device having charge device and said electrodes across said main capacia sealed envelope, transformer means including a plutor, and an impedance connected to said auxiliary capacirality of high voltage transformer secondary windings and tor to control the charge state thereof prior to said are low voltage primary winding means inductively coupled disc arge and to limit the dissipation of the charge enwith said secondary windings, means connecting said ergy of said main capacitor other than in said are dissecondary windings in parallel circuit relation, each branch charge. of the parallel circuit including connections for one pair of said spark ignition electrodes, ilneans corlilnectiig Sal]? References Cited in the file of this patent arallel circuit in series circuit re ation wit sai s ar discharge device across one of said capacitors thereby UNITED STATES PATENTS to provide a main discharge circuit and means connect- 5 Number Name Dat ing said transformer primary winding means and said 2,503,504 Laird Apr. 4, 1950 spark discharge device in series circuit relation across the 2, 46,550 Laird Mar. 27, 1951 other said capacitor, whereby discharge of said other ca- 2,551,101 Debenham et al. May 1, 1951 pacitor induces high voltages in said secondary windings 2, 89,164 Tognola Mar. 11, 1952 thereby to trigger said main discharge circuit, 

